Mechanical Maintenance Technician

About Mariana Minerals

Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We're reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.

The Role

Mariana Minerals is looking for a highly motivated Mechanical Maintenance Technician to join our San Francisco Pilot Plant team. You will support the design, installation, and maintenance of first-of-its-kind refining processes for critical minerals. This position plays a critical role in bridging R&D and Operations, ensuring our equipment and work processes are robust, safe, cost-effective, and suitable for commercial production.

What You’ll Do

• Perform preventive and corrective maintenance on plant equipment including pumps, valves, piping systems, filtration units, and other process equipment.
• Troubleshoot and repair mechanical issues to maintain safe and reliable plant operations.
• Assist with fabrication, installation, modification, startup, and commissioning of new equipment and pilot plant systems.
• Read and interpret engineering drawings, P&IDs, and equipment manuals to support maintenance and installation work.
• Safely perform maintenance activities following plant safety procedures including Lockout/Tagout (LOTO), hot work permitting, and confined space entry.
• Identify and maintain critical spare parts for the pilot plant.
• Champion the site Computerized Maintenance Management System (CMMS) system.

Desired Qualifications

• Associate degree, technical certificate, or equivalent hands-on experience in industrial maintenance, mechanical technology, millwright work, or a related field.
• 3+ years of experience maintaining industrial or pilot-scale equipment in the minerals processing, chemicals, specialty materials, oil & gas, biotech, or similar industries.
• Hands-on experience with maintenance tasks such as pump repair, valve replacement, and instrument troubleshooting.
• Hands-on experience fabricating, modifying, and/or constructing industrial equipment.
• Familiarity with core plant safety practices including Lockout/Tagout (LOTO), hot work permits, confined space entry, and safe work permitting systems.
• Experience documenting maintenance activities using CMMS or maintenance tracking systems.
• Experience working with rotating equipment, filtration systems, and industrial piping is a plus.
• Ability to climb stairs, stand for extended periods of time, and safely lift up to 50 lbs.

Why Join Us?

• You’ll be part of a mission-driven team reshaping the way critical minerals are sourced and supplied globally.
• You’ll have the autonomy to make big decisions, the tools to innovate, and a culture that values ownership, smart automation, and collaboration.
• We celebrate diversity and are committed to creating an inclusive environment for all employees.
• We do not discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, veteran status, or any other protected status.